The scientific discovery of life course determinants and understanding of within-person processes leading to health-related changes and accelerated aging is a major research priority internationally. The study of aging demands an integrative life course developmental framework, involving interdisciplinary collaborations and advanced methodological approaches for understanding how and why individuals change with age, in both normative and idiosyncratic ways. However, longitudinal research can present remarkable challenges. Replication and comparison of results must include consideration of the age range, birth cohort, culture, health and education of individuals in the sample, differences in measurements, design and statistical analysis, and issues such as rates of response, attrition, and mortality selection. In addition, an understanding of life course processes is embedded within an international and historical context, with consideration of country, culture, and historical differences necessary for evaluating reproducibility and generalizability of particular study findings. A vital function of this application is to further develop, maintain, and make use f an infrastructure for coordinated analysis of international longitudinal studies for advancing knowledge about aging-related change and life course determinants of such changes. The aims of the overall program project are: 1) To facilitate collaborative, coordinated, and pooled-data analysis of longitudinal studies of aging through the creation of a purpose-built research platform for aggregating and organizing metadata related to study and measurements; 2) To evaluate the impact of chronic health conditions and health-related biomarkers on aging-related change in cognitive and physical functioning; 3) To evaluate general patterns of population average and individual variation in aging, health, and mortality related change across distinct personality and well-being constructs in major longitudinal studies on aging; and 4) To evaluate the role of early life characteristics and social determinants ion aging-related change in cognition and health, with emphasis on differential risk and exposure processes.